Masutatsu Ōyama, known outside Japan as Mas Oyama, was a renowned martial artist who founded the full-contact karate style known as Kyokushin. While his life story served as the direct inspiration for the manga and anime series Karate Master, known in Japan as Karate Baka Ichidai, he was not the original creator of those works. The authorship of the manga is credited to writer Ikki Kajiwara and illustrators Jirō Tsunoda and Jōya Kagemaru. The story is a dramatized biography of Ōyama's journey, depicting his rigorous training, his philosophy of martial arts, and the establishment of his own karate style.

Ōyama was born Choi Yeong-eui on July 27, 1923, in Korea during a period of Japanese rule. He moved to Japan and adopted the Japanese name Masutatsu Ōyama. After studying various martial arts, including Shotokan and Goju-ryu karate, he developed his own style, Kyokushin, which emphasized full-contact sparring and physical toughness. His legendary feats, such as fighting bulls bare-handed and undertaking the "100-man kumite," became central to his public persona.

The manga Karate Baka Ichidai was serialized in Kodansha's Weekly Shōnen Magazine from 1971 to 1977, running for a total of 29 volumes. The story was explicitly framed as a non-fiction account of Ōyama's life, although it is known to contain significant dramatizations and fictional elements created by Kajiwara. The success of the manga and its subsequent adaptations are credited with sparking a major karate boom in Japan during the 1970s, greatly raising the public profile of both Kyokushin karate and Ōyama himself.

The story was adapted into a 47-episode anime television series that aired from October 1973 to September 1974. This anime production involved studios A Production and Tokyo Movie, with direction by Eiji Okabe and Osamu Dezaki. A notable feature of the anime was its use of live-action footage interspersed with the animation to demonstrate the power of Kyokushin karate. The work was also adapted into a live-action film in 1977 directed by Kazuhiko Yamaguchi and starring Shin'ichi Chiba.

The recurring artistic identity of the Karate Master works centers on the themes of self-discipline, overcoming adversity through sheer willpower, and the pursuit of martial arts mastery. The narrative frequently contrasts Ōyama's superhuman strength with his personal struggles, including poverty, the death of a student, and social isolation. This blend of extreme action and human drama was a hallmark of the story and contributed to its lasting popularity and influence on later fighting manga and video games. The works remain a significant part of martial arts media history, demonstrating how a real-life figure's life could be transformed into a foundational text for an entire genre.